The prior art is already aware of various systems and mechanisms for adjusting a bedknife toward and away from a lawn mower cutting reel. Commonly the bedknife is pivotally mounted to move its cutting edge toward and away from the rotating reel, and the desired positioning of the bedknife cutting edge relative to the reel can be at least somewhat accomplished. Examples of the prior art are disclosed in U.S. Pat. Nos. 3,106,813 and 3,187,492 and 3,680,293 and 4,335,569. These patents generally show either a control lever or a threaded member and/or a spring for influencing the position of the bedknife relative to the reel. However, in all instances, the manual adjustment of the lever, threaded member, or whatever is employed, results in a specific positioning of the bedknife cutting edge, which positioning is established according to the manual adjustment. That is, the operator might inadvertently over or under adjust the setting, and thus the bedknife cutting edge would not be in the optimum position.
The present invention improves upon the prior art, in that it provides a bedknife adjustment system wherein the adjustment is automatic and operator error or the like does not enter into the adjustment. Further, the accomplishment of the aforementioned objective is possible even where the cutting reel and bedknife are new or worn or for other reasons are of variable sizes deviating from the conventional sizes or dimensions. Still additionally, the present invention provides for the optimum bedknife adjustment either in the position of having its cutting edge in contact or no clearance position with the cutting reel, or having the bedknife cutting edge automatically positioned at a desired specified clearance from the cutting reel. In all instances, the adjustment of the bedknife is automatic and operator inexperience, error, or the like does not enter into the consideration in the use of the adjustment system of this invention.
Further, with the present inventive concept, one embodiment thereof permits the adjustment with a specified clearance between the bedknife cutting edge and the reel, and another embodiment thereof permits the adjustment where there is no clearance therebetween. In both instances, the adjustment can be repeated and the same positioning can be achieved automatically with each adjustment. Therefore, from time to time in the use of the mower, the adjustment can be again accomplished, and that adjustment will be the same as the specified and previous adjustments, and it will be automatically accomplished and free of operator variations for whatever reason.
Still further, the present invention accomplishes all of the aforementioned objectives, and it also provides an arrangement whereby the bedknife will automatically move away from the cutting reel when any debris is between the bedknife and the cutting reel. Therefore, the present invention protects the lawn mower against damage which might otherwise occur due to debris being lodged between the bedknife cutting edge and the reel, including damage of dulling or marring the cutting surfaces.
Other objects and advantages will become apparent upon reading the following description in light of the accompanying drawings.